Basic information
| Field | Details |
|---|---|
| English / full name | IPv6 and Egress-only Internet Gateway |
| Chinese | IPv6 与仅出站互联网网关 |
| Japanese | IPv6 と Egress-only Internet Gateway |
| Review priority | 考试频率 ⭐⭐⭐⭐ |
| Often confused with | Internet Gateway / NAT Gateway / NAT64 / Dual Stack |
In one sentence
An EIGW gives publicly routable IPv6 workloads outbound-only internet access, permits related return traffic, and performs no NAT.
Core summary
IPv4 and IPv6 have separate CIDRs, routes, and security rules. A ::/0 route to the EIGW controls IPv6-initiated egress.
Study points
- Use an EIGW for outbound-only IPv6-to-IPv6 traffic.
- Use DNS64 and NAT64 when an IPv6 client must reach an IPv4-only target.
- A dual-stack subnet can still exhaust IPv4 addresses.
- A routable IPv6 address does not remove security group or NACL controls.
Common pitfalls
- 0.0.0.0/0 does not cover IPv6, and ::/0 does not cover IPv4.
- An EIGW does not translate addresses or provide IPv6-to-IPv4 conversion.
Key memory
EIGW for outbound IPv6-to-IPv6; NAT64 for IPv6-to-IPv4 translation.